1. Field of the Invention
The present invention relates generally to medical systems and methods. More particularly, the present invention relates to systems and methods for stenting aortic and other bifurcations while preserving contralateral arterial access.
The use of endoluminal prostheses for treating vascular and other diseases has become wide-spread over the past several decades. Endoluminal prostheses, commonly known as stents, are used to maintain the patency of blood vessels and other body lumens. Stents are typically formed as tubular metal scaffolds which can be expanded in situ from a relatively small diameter to a larger diameter sufficient to maintain the desired level of patency. The stents or other vessel scaffolds can be covered with fabrics or membranes, in which case they are commonly referred to grafts.
The use of both stents and grafts has become wide-spread and has revolutionized many medical treatments. Despite the wide success, the treatment of certain anatomies still presents challenges. For example, the treatment of atherosclerotic lesions in bifurcated blood vessels, where a main vessel divides into two branches, can be difficult. For example, occlusive disease frequently occurs at the bifurcation of the aorta into the iliac arteries. While such bifurcation disease may be successfully treated by using a pair of vascular grafts where one graft is placed in each iliac artery and the grafts are disposed side-by-side in the aorta (commonly referred to as “kissing stents”), such treatment makes subsequent contralateral access to treat future disease more difficult.
Referring to FIGS. 1A and 1B, the nature of occlusive disease which occurs at the bifurcation of an aorta A into an ipsilateral iliac artery IIA and a contralateral ipsilateral artery CIA will be described. The occlusive disease may be only partial, as illustrated in FIG. 1A, where the lumen of neither the ipsilateral nor the contralateral iliac arteries is fully occluded. In other cases, as illustrated in FIG. 1B, at least one of the ipsilateral and contralateral iliac lumens will be completely blocked, referred to as a chronic total occlusion CTO. Treatments for these two different conditions will vary, as described in detail below in connection with the present invention. Presently, however, for both conditions the most common treatments is the placement of an ipsilateral stent or graft IS in the ipsilateral iliac artery IIA and a contralateral stent or graft CS in the contralateral iliac artery CIA, as shown in FIG. 2 (the so-called kissing stents referred to earlier). While the resulting stent or graft structures provide excellent recanalization of the aorta and the branching iliac arteries, the structure also makes it very difficult to achieve subsequent contralateral access from an ipsilateral iliac artery. Without the stent or graft structures in place, it will be appreciated that a guidewire placed in through an ipsilateral iliac artery can be easily passed over the carina C into a contraleteral iliac artery once the occlusive disease has been penetrated or bypassed. The “kissing stents” IS and CS, in contrast, form a boundary between the iliac arteries that makes it very difficult to advance a guidewire from the ipsilateral iliac artery IIA to the contralateral iliac artery CIA. Thus, subsequent treatment of disease at or near the aortic bifurcation can be much more difficult, often requiring open surgery rather than an endoluminal treatment.
For these reasons, it would be desirable to provide improved systems and methods for treating occlusive and other disease at the aortic and other vascular and non-vascular vessel bifurcations. The systems and methods should be able to provide the improved patency achieved by the “kissing stents” of the prior art, while preserving the ability to subsequently access a contralateral lumen from an ipsilateral lumen by advancing a guidewire over the carina with minimum inhibition. The methods and systems should be compatible with both totally and partially occluded lumens, and in the case of aortic disease, it should facilitate passage of a guidewire through a totally occluded ipsilateral iliac artery into a contralateral iliac artery. At least some of these objectives will be met by the inventions described below.
2. Description of the Background Art
Systems and methods for manipulating guidewires and bypassing occlusions in the peripheral vasculature are described in US20140142677; US20140142677; US20070173878; US20030236566: US20030236566; US20040148005; US2008016901; US20060047222: US20080065019.